Probe card and semiconductor testing device using probe sheet or probe card semiconductor device producing method

ABSTRACT

A probe card, and a probe sheet used for the method of testing (producing) a semiconductor device using the probe card, include first contact terminals in electrical contact with the electrodes of a test object formed at a narrow pitch, wires connected with and led from the first contact terminals, and second contact terminals in electrical contact with the wires. The first and second contact terminals are formed using the etching holes of a crystalline member and lined with a metal sheet.

TECHNICAL FIELD

This invention relates to a probe card, a semiconductor testing deviceusing the probe sheet or the probe card and a semiconductor deviceproducing method.

BACKGROUND ART

An example of the flow of the testing steps included in thesemiconductor device producing steps executed after forming asemiconductor element circuit on a wafer is mainly shown in FIG. 12,taking a packaged product, a bare chip and a CSP providing arepresentative form of shipment of the semiconductor device.

The tests conduced in the semiconductor device producing process areroughly divided into three as shown in FIG. 12, including a wafer testwhich is conducted on a wafer formed with a semiconductor elementcircuit and an electrode thereon to determine the conduction and theelectrical signal operation of the semiconductor elements, a burn-intest for picking out an unstable semiconductor element at a hightemperature or under a high applied voltage, and a select test for theproduct performance before shipment of the semiconductor device.

A conventional device (semiconductor test device) used for these testsof the semiconductor device is described in U.S. Pat. No. 5,461,326. Thetechnique described in U.S. Pat. No. 5,461,326 is implemented by aself-horizontalization thin film test probe comprising a thin filmsupport frame, a flexible thin film fixed on the support frame, aplurality of test probe contactors arranged in the central area of theouter surface of the thin film in such a manner as to apply pressure ona contact pad of the device to be tested, a plurality of conductivetraces on the thin film for connecting each probe contactor to a testcircuit, and a means (including a pressure plate fixed on the innersurface of the thin film in the central area and a pivot post with ahemispherical head for applying pressure pivotally to the center of thepressure plate) for automatically rotating the central area of the thinfilm under the pressure applied by the probe test contactor onto thecontact pad of the device to be tested.

Another conventional technique is described in U.S. Pat. No. 6,305,230.U.S. Pat. No. 6,305,230 discloses a technique implemented by aconnecting device including a support member, a multilayer film having aplurality of contact terminals with a sharp tip arranged in theprobing-side area thereof and a ground layer with a plurality of leadwires electrically connected and led to each contact terminal through aninsulating layer, a frame fixed on the reverse side of the multilayerfilm, a holding member, a contact pressure application means forapplying the contact pressure to the holding member from the supportmember to bring the tip of each contact terminal into contact with eachelectrode, and a compliance mechanism for projecting the tip surfaces ofthe contact terminals in parallel along the surface of the electrodeswhen the tip surfaces of the contact terminals are brought into contactwith the surfaces of the electrodes, and an test system for conductingthe test by electrically connecting the connecting device brought intocontact with the electrodes of the test object.

DISCLOSURE OF THE INVENTION

According to U.S. Pat. No. 5,461,326, however, the peripheral portion ofthe thin film is fixed to apply pressure to the contact terminals withthe whole thin film tightly extended. The parallel projection of thepressure plate and the test object depends on the tension of the thinfilm. Also, in the case where the thin film is extended from the lowersurface of the wiring board, a large tensile force is exerted on thethin film, and therefore the wire is liable to break. Thus, the amountof extension of the thin film is limited.

Also, the extended state of the thin film expands the arrangement of thetip of each contact terminal and makes it difficult to secure theaccuracy of the tip position. Further, the pivot post and the pressureplate lack an initial parallel projection mechanism, and therefore areliable to be tilted and come into a sided contact with the test object,thereby increasing the chance of the test object being damaged.

According to U.S. Pat. No. 6,305,230, on the other hand, both thecontact pressure load control and the parallel projection are carriedout by a spring probe arranged around a center pivot. It is difficult,therefore, to set a spring pressure making possible both controloperations at the same time. Further, the problem is that the holdingmember is displaced horizontally. Also, the positional accuracy of thetip of each contact terminal is delicately varied with the expansion ofthe thin film, and therefore it is difficult to secure the accuracy ofthe tip position.

As described above, none of the techniques described in theabove-mentioned US Patents is satisfactory in view of the fact that theprobing corresponding to the multiple pins with a narrow pitch due tothe increased density of the test object such as a semiconductor elementcannot be realized with a low load and a simple assembly while securingthe positional accuracy of the tip of the contact terminals withoutdamaging the test object and the contact terminals.

Also, with the recent increased integration of the semiconductorelements, the electrode pitch has been reduced (to less than about 0.1mm, for example) and the density thereof increased more and more. Inaddition, the current tendency is to conduct the operation test at ahigh temperature (for example, 85° C. to 150° C.) to secure thereliability more positively, and therefore demand has arisen for thetest device meeting this requirement.

The object of this invention is to provide a probe card having a probesheet and an test method and apparatus using the probe card or the probesheet in which the accuracy of the tip position of the contact terminalsis secured and semiconductor elements having an electrode structure ofnarrow pitches can be positively test.

In order to achieve the aforementioned object, this applicationdiscloses the invention of which representative aspects are brieflydescribed below.

-   (1) A probe card comprising a plurality of contact terminals in    contact with an electrode arranged on a test object, wires led from    the contact terminals and a multilayer wiring board having    electrodes electrically connected with the wires, wherein the    electrodes of the multilayer wiring board and the wires are    electrically connected to each other through peripheral electrodes.-   (2) A probe card including a probe sheet having a multilayer wiring    board electrically connected to a tester for testing the electrical    characteristics of a test object and a plurality of contact    terminals in contact with a plurality of peripheral electrodes    connected to the electrodes of the multilayer wiring board and the    electrodes arranged on the test object, wherein the probe sheet    further includes a first metal film formed to surround the plurality    of the contact terminals and a second metal film formed to surround    the first metal film.-   (3) A semiconductor device producing method comprising the steps of:

forming semiconductor elements by building circuits in a wafer;

testing the electrical characteristics of the semiconductor elements;and

separating each semiconductor element by dicing the wafer;

wherein the step of testing the electrical characteristics of thesemiconductor elements uses a probe sheet having a plurality of contactterminals in contact with the electrodes of the semiconductor elements,a first metal film formed to surround the plurality of the contactterminals and a second metal film formed to surround the first metalfilm; and

wherein pressure is applied to the area formed with the first metal filmand the area formed with the plurality of the contact terminals of theprobe sheet, while testing by bringing the plurality of the contactterminals into contact with the electrodes formed on the semiconductorelements.

The other objects, features and advantages of this invention will bemade apparent by the following description of the invention withreference to the accompanying drawings.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the invention are described in detail below withreference to the drawings. In each drawing attached hereto forexplaining the embodiments of the invention, the component elementshaving the same function are designated by the same reference numerals,respectively, and not described again.

In this specification, the main terms are defined as follows.Specifically, the “semiconductor device” may be in any form including awafer formed with a circuit (FIG. 1A, for example), a semiconductorelement (FIG. 1B, for example) or a subsequently formed package (QFP,BGA, CSP, etc.). FIG. 1B shows an example of the test object, in whichthe electrodes 3 may be arranged either along the periphery or over thewhole surface. The “probe sheet” is defined as a sheet having thecontact terminals in contact with the electrodes of the test object andthe wires led out from the terminals. The “probe card” is defined as astructure (such as shown in FIGS. 2A, 2B) connected to the electrodes ofthe test object and functioning as a connector for electricallyconnecting a tester providing a measuring instrument and the testobject.

The structure of the probe card according to the invention is explainedwith reference to FIGS. 2A, 2B and 3A, 3B.

FIG. 2A is a sectional view showing the essential parts of the probecard according to a first embodiment of the invention. FIG. 2B is aexploded perspective view of the essential parts. The probe cardaccording to the first embodiment comprises a support member (upperfixing plate) 7, a spring probe 12 fixed adjustably along the height ofthe central portion of an intermediate plate 24 screwed to the supportmember 7 and including a lower forward end protrusion 12 a acting as acenter pivot and a spring 12 b for applying pressure to the probe sheet6 through a push piece 22 movable with the forward end of the protrusion12 a as a fulcrum, a frame 21 fixedly bonded to the reverse surface insuch a manner as to surround the area formed with the plurality of thecontact terminals 4 of the probe sheet 6, and an intermediate plate 24screwed to the frame 21 and having a buffer member 23 of a siliconesheet or the like and the push piece 22 at the central portion thereofbetween the frame 21 and the reverse surface of the area formed with thecontact terminals 4 of the probe sheet 6. This support member 7 includesparallel projection adjust screws 25 whereby the surface of the probecard having the contact terminals 4 and the corresponding electrodesurface having the semiconductor elements are projected in parallel.

This probe card uses a compliance mechanism having such a structure thata substantially constant desired pressure (about 20 N for the pushamount of 150 μm with almost 500 pins, for example) is applied by thespring probe 12 against the push piece 22 held finely tiltably on theprotrusion 12 a at the forward end of the spring probe 12 arranged atthe central portion of the intermediate plate 24, with the result that asubstantially constant desired pressure is applied to the area formedwith a plurality of the contact terminals. The central portion of theupper surface of the push piece 22 is formed with a conical groove 22 aadapted to engage the protrusion 12 a.

In the probe sheet 6, as shown in FIGS. 2A, 2B, a plurality of thecontact terminals 4 adapted to come into contact with the electrodes 3of the semiconductor elements 2 are formed at the central area on theprobing side of the sheet, the contact terminals 4 are surrounded in twolayers by a metal film 30 a and a metal film 30 b in the areacorresponding to the frame 21, a plurality of peripheral electrodes 5for applying and receiving signals to and from the multilayer wiringboard 50 are formed on the peripheral portion on the four sides of theprobe sheet 6, a metal film 30 c is formed in the area corresponding toeach peripheral electrode fixing plate 9 in such a manner as to surroundthe peripheral electrodes 5, and a multiplicity of lead wires 20 areformed between the contact terminals 4 and the peripheral electrodes 5.Further, the frame 21 is fixedly bonded on the reverse surface of theprobe sheet 6 in the area formed with the contact terminals 4, and theperipheral electrode fixing plates 9 are fixedly bonded on the reversesurface of those portions of the probe sheet 6 for applying andreceiving the signals which are formed with the peripheral electrodes 5,respectively. Further, the frame 21 is screwed to the intermediate plate24. On this intermediate plate 24, the spring probe 12 is fixed and aprotrusion 12 a at the lower forward end thereof is adapted to engage aconical groove 22 a formed at the central portion of the upper surfaceof the push piece 22.

In the case where the plurality of the contact terminals 4 have acentral space, the metal film 30 a may be formed with a metal film 30 dat the central portion thereof, as shown in FIG. 3B. Also, the assemblyperformance can be improved by forming a pattern of a positioning knockpin 30 e and a screw insertion hole 30 f in advance on the metal film 30c.

As shown in FIG. 13, for example, the whole assembly is set in positionusing the knock pin holes 30 e for positioning the metal films 30 c, thecorresponding knock pin holes 50 e of the multilayer wiring board 50,the knock pin holes 33 e of the lower holding plate 33 and the knock pinholes 9 e of the peripheral electrode fixing plates 9. In this way, theperipheral electrode fixing plate 9 is fixedly screwed to the lowerholding plate 33. Next, each peripheral holding plate 32 is set inposition by the knock pin 34 using the knock pin hole 9 e of theperipheral electrode fixing plate 9 and the knock pin hole 32 e of theperipheral holding plate 32 through the buffer member 31 on thecorresponding one of the peripheral electrode fixing plates 9 fixedaround the peripheral electrodes 5 on the probe sheet 6, and thenfixedly screwed to the lower holding plate 33. In this way, theperipheral electrodes 5 are connected under pressure to the electrode 50a of the multilayer wiring board 50 through the buffer member 31.

Then, a circular metal film 30 a and a metal film 30 b are formed (inthe area corresponding to the frame 21) in such a manner as to surroundthe contact terminals 4 of the probe sheet 6 in double layers. Thus, astructure is realized in which the positional accuracy of the contactterminals is secured by the inner metal film 30 a and the copy operationis possible while tilting the portion lined with the metal film at adelicate angle to the wafer surface to be contacted, in the flexibleprobe sheet area free of the metal film 30 between the metal film 30 bformed in the area corresponding to the frame 21 and the inner metalfilm 30 a. Specifically, a plurality of the contact terminals 4 aresurrounded by the metal film 30 a so that an extraneous stress isprevented from being applied to the area formed with the contactterminals at the time of test operation, and an accurate contact isrealized with the electrode to be tested. In addition, the use of themetal film 30 of a material such as the 42 alloy or invar havingsubstantially the same coefficient of linear expansion as the siliconwafer makes it possible that the metal film 30 substantially coincideswith the test object (silicon wafer) in performance while at the sametime securing the positional accuracy at the tip of the contactterminals even at high temperatures.

Also, a metal film 30 c is formed in the area corresponding to eachperipheral electrode fixing plate 9 in such a position as to surroundthe peripheral electrodes 5 on the periphery of the probe sheet 6described above. Thus, the strength of the probe sheet 6 while at thesame time securing the positional accuracy of the peripheral electrodesand facilitating the assembly operation. The assembly operation isfurther facilitated by forming positioning holes and screw insertionholes high in both positional accuracy and shape by collectively etchingthe metal films 30 c using a photolithographic mask.

The connecting device according to a second embodiment of the inventionis explained with reference to FIGS. 3A, 3B. FIG. 3A is a sectional viewshowing the essential parts of the connecting device according to thesecond embodiment of the invention, and FIG. 3B an exploded perspectiveview of the particular essential parts. The connecting device accordingto the second embodiment is different from the connecting deviceaccording to the first embodiment in that a spring plunger 13 and aprojected holding pin 14 are used in place of the spring probe 12 as ameans for applying pressure to the push piece 22, that a structure isused in which an intermediate plate 24 with the spring plunger 13 fixedthereon and a support member 7 are held movable by a spring plate 15, orthat in the case where the contact terminals 4 of the metal film 30 ahave a central space, a metal film 30 d is formed in the centralportion. Any of these differences can be combined, whenever required,with the structure disclosed in the first embodiment.

The compliance mechanism for applying a substantially constant desirepressure is not limited to the one included in the embodiment describedabove but can be variously altered.

Next, a method of producing an example of the probe sheet (structure)used with the probe card described above is explained with reference toFIGS. 4A to 4H.

FIGS. 4A to 4H show a production process, step by step, to form theprobe card shown in FIGS. 2A, 2B, or especially, a process in which thetruncated pyramidal tip of each contact terminal and the lead wire 20are formed integrally with a polyimide sheet using truncated pyramidalholes formed by anisotropic etching in the silicon wafer 80 as a moldmember, and a metal film is coupled to the polyimide sheet by apolyimide adhesive sheet, thereby forming a probe sheet 6 with areinforcing plate and positioning knock pin holes formed by etching onthe metal film.

First, the step shown in FIG. 4A is executed. At this step, a silicondioxide film 81 about 0.5 μm thick is formed by thermal oxidation onboth sides of the (100) surface of a silicon wafer 80 having thethickness of 0.2 to 0.6 mm, and coated with a photoresist. A patternwith the photoresist removed from the positions where the truncatedpyramidal holes are to be formed is removed by photolithography, afterwhich the silicon dioxide film 81 is etched off by a mixture solution ofhydrofluoric acid and ammonium fluoride with the photoresist as a mask.Then, with the silicon dioxide film 81 as a mask, the silicon wafer 80is anisotropically etched by a strong alkali solution (such as potassiumhydroxide) thereby to form truncated pyramidal etching holes 80 asurrounded by the (111) surface.

According to this embodiment, the silicon wafer 80 is used as a moldmember. Nevertheless, the mold member can be formed of any crystallinematerial and of course modified variously without departing from thislimitation. Also, the shape of each hole formed by anisotropic etchingaccording to the embodiment is not necessarily truncated pyramid but maybe variously modified as long as the contact terminals 4 can be formedto secure a stable contact resistance under a small stylus pressure.Also, the electrode to be contacted can of course be contacted by aplurality of contact terminals.

Next, the step shown in FIG. 4B is executed. At this step, the silicondioxide film 81 used as a mask is etched off by a mixture solution ofhydrofluoric acid and ammonium fluoride, and the whole surface of thesilicon wafer 80 is again formed with a silicon dioxide film 82 to thethickness of about 0.5 μm by thermal oxidation in wet oxygen. Theresulting surface is formed with a conductive film 83, and the surfaceof the conductive film 83 is formed with a polyimide film 84. Then, thepolyimide film 84 located at the positions where the contact terminals 4are to be formed is removed to the depth reaching the surface of theconductive film 83.

The conductive film 83 is formed in such a manner that a chromium filmabout 0.1 μm thick is formed by sputtering or vapor deposition, and theresulting surface is sputtered or deposited by evaporation with copperto form a copper film about 1 μm thick. This copper film may be platedwith copper to the thickness of several μm to increase the resistance tolaser machining. To remove the polyimide film 84, the laser boring orthe dry etching is used by forming an aluminum mask on the surface ofthe polyimide film 84.

Next, the step shown in FIG. 4C is executed. The conductive film 83exposed to the openings of the polyimide film 84 is electrically platedwith a material of high hardness as a main component using theconductive film 83 as an electrode thereby to form the contact terminals4 and the connecting electrodes 4 b integrally. Plating materials ofhigh hardness including nickel 8 a, rhodium 8 b and nickel 8 c areplated sequentially thereby to form each contact terminal portion 8having the contact terminal 4 and the connecting electrode portion 4 bintegrated with each other.

Next, a conductive film 86 is formed on each contact terminal portion 8and the polyimide film 84, and after forming a photoresist film 87, awiring material 88 is plated.

The conductive film described above is formed by sputtering or vapordeposition of chromium. In this way, a chromium film about 0.1 μm thickis formed and the resulting surface is formed with a copper film about 1μm thick by sputtering or vapor deposition. Copper is used as the wiringmaterial.

Next, the step shown in FIG. 4D is executed. At this step, thephotoresist mask 87 is removed, and with the wiring material 88 as amask, the conductive film 86 is removed by soft etching, after which anadhesive layer 89 and a metal film 30 are formed, followed by forming aphotoresist mask 91 on the metal film 30.

The adhesive layer 89 is formed using a polyimide adhesive sheet or anepoxy adhesive sheet. The metal film 30 is formed of a metal sheethaving a low coefficient of linear expansion such as the 42 alloy (analloy containing 42% nickel and 58% iron having a coefficient of linearexpansion of 4 ppm/° C.) or invar (an alloy containing 36% nickel and64% iron having a coefficient of linear expansion of 1.5 ppm/° C.)substantially equal to the coefficient of linear expansion of thesilicon wafer (silicon mold member) 80. This metal sheet is attached onthe polyimide film 84 formed with the wiring material 88 using theadhesive layer 89. In this way, the probe sheet 6 formed has an improvedstrength and a larger area. Also, the displacement with temperature isprevented at the time of testing, and the positional accuracy can besecured in various environments. For this reason, the metal film 30 isformed of a material having a coefficient of linear expansionsubstantially equal to that of the semiconductor element to be tested tosecure the positional accuracy at the time of the burn-in test.

At the bonding step described above, the silicon wafer 80 formed withthe polyimide film 84 having the contact terminal portions 8 and thewiring material 88 is superposed on the adhesive layer 89 and the metallayer 30, while applying the pressure of 10 to 200 Kgf/cm², heated tohigher than the glass transition point temperature (Tg) of the adhesivelayer 89 and bonded in vacuum with heat under pressure.

Next, the step shown in FIG. 4E is executed. At this step, after etchingthe metal film 30 with the photoresist mask 91, a process ring 95 isfixed on the metal film 30 by an adhesive 96, and after bonding aprotective film 97 on the process ring 95, the silicon dioxide film 82is etched off by a mixture solution of hydrofluoric acid and ammoniumfluoride with a protective film 98 having a central opening as a mask.In the case where the metal film 30 is formed of a 42 alloy or invarsheet, for example, the spray etching is conducted with a ferricchloride solution. Alternatively, the photoresist mask is formed ofeither a liquid resist or a film resist (dry film).

Next, the step shown in FIG. 4F is executed. At this step, theprotective films 97, 98 are removed, and by mounting a protective jig100 for silicon etching, the silicon is etched off. For example, theprocess ring 95 is screwed to an intermediate fixing plate 100 d, andmounted between a fixing jig 100 a of stainless steel and a cover 100 bof stainless steel through an O-ring 100 c. Then, the silicon wafer 80providing a mold material is etched off by a strong alkali solution(such as potassium hydroxide).

Next, the step shown in FIG. 4G is executed. At this step, theprotective jig 100 for silicon etching is removed, a protective film isbonded to the process ring 95 as in FIG. 4D, the silicon dioxide 82, theconductive film 83 (chromium and copper) and the nickel 8 a are etchedoff, and after removing the protective film, an adhesive 96 b is appliedbetween the frame 21 and the metal film 30 b and between the peripheralelectrode fixing plate 9 and the metal film 30 c of the probe sheetthereby to fix the metal film 30 in position.

The silicon dioxide film 82 is etched off by a mixture solution ofhydrofluoric acid and ammonium fluoride, the chromium film by apotassium permanganate solution, and the copper film and the nickel film8 a by an alkalic copper etching solution.

The rhodium plating 8 b exposed to the surface of the contact terminalsas the result of this series of etching process is used by reason of thefact that solder or aluminum constituting the material of the electrode3 is hard to attach to the rhodium plating 8 b which is higher inhardness, harder to oxidize and has a more stable contact resistancethan nickel.

Next, the polyimide film 84 and the adhesive layer 89 integrated alongthe outer periphery of the probe sheet frame 21 and the peripheralelectrode fixing plate 9 are cut out, thereby forming a probe sheetadapted to be mounted on the probe card 105.

Next, a method of producing the probe sheet according to a secondembodiment somewhat different from the above-mentioned probe sheetproduction process is explained with reference to FIGS. 5A to 5E.

FIGS. 5A to 5E show another production process, step by step, to form aprobe sheet.

First, truncated pyramidal etching holes 80 a are formed in a siliconwafer 80 shown in FIG. 4A, a silicon dioxide film 82 is formed on theresulting surface, a conductive film 83 is formed thereon, and aphotoresist mask 85 with open connection terminal portions 8 is formedon the surface of the conductive film 83.

Next, using the photoresist mask 85 shown in FIG. 5B, the electricalplating is conducted with the conductive film 83 as a power feed layerthereby to form the contact terminals 4 a and the connecting electrodeportion 4 b integrally with each other. Then, the photoresist mask 85 isremoved. The plating materials including nickel 8 a, rhodium 8 b andnickel 8 c, for example, are sequentially plated so that the contactterminal 4 a and the connecting electrode portion 4 b are integrallyformed into each contact terminal portion 8.

Next, the step shown in FIG. 5C is executed. At this step, a polyimidefilm 84 b is formed in such a manner as to cover the contact terminalportions 8 and the conductive film 83, and the portion of the polyimidefilm 84 b located at positions where the wiring connection holes leadingfrom the corresponding contact terminal portions 8 are to be formed isremoved up to the surface of the contact terminal portions 8 thereby toform the conductive film 86 on the polyimide film 84 b. After formingthe photoresist mask 87, the wiring material 88 is plated.

To remove a part of the polyimide film 84 b, the laser boring process orthe dry etching process with an aluminum mask formed on the surface ofthe polyimide film 84 b is used.

The conductive film described above is, for example, a chromium filmabout 0.1 μm thick formed by sputtering or vapor deposition, andfurther, the surface of the chromium is formed with a copper film about1 μm thick by sputtering or vapor deposition. Also, the wiring materialis plated with copper or copper and nickel.

Next, the step shown in FIG. 5D is executed. At this step, thephotoresist mask 87 is removed and the conductive film 86 is etched offwith the wiring material 88 as a mask, after which an adhesive layer 89and a metal layer 90 are bonded. Then, the metal film 90 is etched usinga photoresist mask thereby to form the desired metal film pattern.

Next, through the steps similar to those shown in FIGS. 4E to 4G, aprobe sheet mounted on the probe card 105 is completed as shown in FIG.5E.

A method of producing the probe sheet according to a third embodiment isexplained with reference to FIGS. 6A to 6G.

The probe sheet producing method according to this embodiment is similarto that described in FIGS. 4A to 4H, 5A to 5H, except that a platingfilm for selective etching is initially formed. The selective platingfilm 61 is used to secure the height (the amount projected from thepolyimide film) of the contact terminals. In this production steps, evenin the case where the contact terminals are produced with the holesformed by anisotropic etching as a mold member, the contact terminalsnarrow in pitch and high in density can be maintained while making itpossible to adjust the height thereof independently and freely.

An example of the production method to form the probe sheet using theselective plating film 61 is explained below with reference to FIGS. 6Ato 6G.

First, the step shown in FIG. 6A is executed. At this step, like atsteps shown in FIGS. 4A, 4B, pyramidal etching holes are formed in thesilicon wafer 80, and the resulting surface is formed with a silicondioxide film 82 and a conductive film 83. Unlike in FIG. 4B, however, apattern of a photoresist 60 or a dry film is formed at the portioncorresponding to each contact terminal portion 8.

Next, the step shown in FIG. 6B is executed. With the conductive film 83as an electrode, the selective plating film 61 is plated. The selectiveplating film 61 of copper 10 to 50 μm thick is an example.

Next, the step shown in FIG. 6C is executed. At this step, a chromiumfilm is formed on the surfaces of the photoresist 60 and the selectiveplating film (copper plated layer) 61, and the resulting surface isformed with a polyimide film 62. Then, an aluminum mask 63 is formed onthe surface of the polyimide film 62. The chromium film about 0.1 μmthick is formed in order to secure the adhesion with polyimide in theprocess, and the chromium film may be done without.

Next, the step shown in FIG. 6D is executed. At this step, using thealuminum mask 63 formed on the surface of the polyimide film 62, theportion of the polyimide film 62 and the photoresist 60 corresponding toeach contact terminal portion 8 is removed by laser or dry etching.

Next, the step shown in FIG. 6E is executed. At this step, the aluminummask 63 is removed, and with the conductive film 83 and the selectiveplating film 61 as an electrode, a material high in hardness as a maincomponent is electrically plated, so that each contact terminal 4 a andthe corresponding connecting electrode portion 4 b are formedintegrally. The plating materials high in hardness include nickel 8 a,rhodium 8 b and nickel 8 c sequentially plated so that each contactterminal 4 a and the corresponding connecting electrode portion 4 b areintegrated into the contact terminal portion 8.

Next, at steps similar to those shown in FIGS. 4C to 4E, the desiredpattern of the lead wires 88 and the metal film 30 shown in FIG. 6F isformed.

Next, at steps similar to those shown in FIGS. 4E to 4G, the probe sheetshown in FIG. 6G is formed.

With regard to the method of producing a probe sheet according to afourth embodiment, the production steps thereof are explained withreference to FIGS. 7A to 7E2.

This probe sheet producing method is similar to the method described inFIGS. 4A to 4H, 5A to 5E except that a plating film is initially formedfor selective etching, like in FIGS. 6A to 6G, to secure the height(amount projected from the polyimide film) of the contact terminals. Thedifference from the steps shown in FIGS. 6A to 6G is that thephotoresist 60 formed at the portion corresponding to each contactterminal portion 8 is removed and the contact terminal portion is alsofilled with polyimide integrally.

An example of the producing method to form the probe sheet using theselective plating film 61 is explained below with reference to FIGS. 7Ato 7E2.

First, the step shown in FIG. 7A is executed. At this step, like in FIG.6B, pyramidal etching holes are formed in the silicon wafer 80, and theresulting surface is formed with a silicon dioxide film 82 and aconductive film 83, and a pattern of a photoresist 60 or a dry film isformed at each portion corresponding to the contact terminal portion 8.Then, with the conductive film 83 as an electrode, a selective platingfilm 61 is formed. After that, the photoresist 60 is removed from theentire surface including the surface of the conductive film 83, and thena chromium film 64 is formed, so that a polyimide film with thepolyimide 62 a filled integrally in the contact terminal portions isformed. In this case, the chromium film can be done without.

Next, at steps similar to those of FIGS. 6D to 6G, the probe sheet shownin FIG. 6G is formed.

As shown in FIGS. 7C, 7D, with a metal film as a mask, the portion ofthe polyimide adhesive layer and the polyimide film around the contactterminal portions may be removed by laser or dry etching, and a bridgewith the contact terminal portion reinforced by the metal film and thecontact terminal portion supported by the wiring material or acantilever beam as shown in FIG. 7E may be formed.

The structure including the bridge or the cantilever beam can increasethe amount of absorbing the height variations of the contact surfaces ofthe contact terminals. Also, the structure of these twin and cantileverbeams can of course be formed by other probe sheet producing methods insimilar fashion.

The production steps of a probe sheet producing method according to afifth embodiment are explained with reference to FIGS. 8A to 8D.

In this probe sheet producing method, each contact terminal portion 8 isformed using the photoresist 65, and after removing the photoresist 65and exposing the contact terminal portions 8, a polyimide film 84 b iscovered. Then, a part of the polyimide film 84 b is removed thereby toform the lead wires 88. Except for this point, the producing methodaccording to this embodiment is similar to that described in FIGS. 6A to6G.

An example of the producing method according to this embodiment isexplained below with reference to FIGS. 8A to 8D.

First, the step shown in FIG. 8A is executed. At this step, like inFIGS. 6A to 6E, using the pattern of the photoresist 65 on the surfaceof the selective plating film 61, the contact terminal portions 8 areformed with the pyramidal etching holes formed in the silicon wafer 80as a mold member. In place of the polyimide film 62 shown in FIG. 6C orthe polyimide film 62 a shown in FIG. 6B, the photoresist 65 easy toremove is preferably used.

Next, the step shown in FIG. 8B is executed. At this step, thephotoresist 65 is removed and the reverse surface portions of thesilicon wafer 80 corresponding to the contact terminal portion 8 areexposed and covered by the polyimide film 86 b, after which the aluminummask 63 a is formed.

Next, the step shown in FIG. 8C is executed. At this step, the portionof the polyimide film 84 b connected to each lead wire 88 is removed upto the surface of the corresponding contact terminal portion 8 using thealuminum mask 63 a, after which at a step similar to FIG. 6F, a patternof the lead wires, the adhesive layer 89 and the metal film 30 isformed.

Next, at steps similar to FIGS. 4E to 4G, the probe sheet shown in FIG.8D is formed.

Several methods of producing the probe sheet are described above, andthe steps of these methods can be appropriately combined as required.

In order to prevent the disturbances of the electrical signal as far aspossible as a probe for high-speed electrical signal inspection, theprobe sheet is produced in a structure with the surface (two or onesurface) thereof or through a ground layer. For example, the surfacehaving a metal film pattern is formed with a film of a conductivematerial by sputtering. The material of the sputtered film includeschromium, titanium, copper, gold, nickel or any combination thereof.

Also, the metal film 30 may be left intact and can be used as a groundlayer 70 as far as possible. As shown in FIG. 9, a copper film is formedas a multilayer film between the metal film 30 and the adhesive layer 89on the lead wire 20 and may be used as a ground layer 70. As analternative, as shown in FIG. 10, the silicon wafer 80 is etched offimmediately after the step of FIG. 4F, and when the conductive film 83is exposed to the surface, a photoresist mask is formed thereby to formthe ground layer 70 with the conductive film 83.

The method of forming the ground layer of the probe sheet describedabove is of course applicable with equal effect to any of the probe cardproducing methods shown in FIGS. 4A to 8D.

FIGS. 14A, 14B show an example of the probe sheet 6 for installingmounting parts 72 such as a capacitor and a resistor for the purpose ofpreventing the disturbances of the electrical signal in the neighborhoodof the contact terminals and thus making possible the electrical signaltest at higher speed. FIG. 14A is a sectional view showing the groundlayer 70 and the power layer 71 in sheet form and sequentially stackedinto a probe sheet 6 to which the mounting part 72 is connected. FIG.14B is a plan view schematically showing the probe sheet 6 with thesurface thereof connected to the mounting parts 72. In the case wherethe mounting parts 72 are connected to the probe sheet 6 in the stateshown in FIG. 14B, for example, the wiring width of the ground wire andthe power wire is increased as far as possible to reduce the wiringresistance. The ground wire and the power wire are thus arrangedadjacently (as a pair wire) to each other, and the insulating layer forthe portions of the parts mounted on each wire corresponding to theconnecting electrodes is formed with via-forming holes 72 a by theboring technique such as laser or dry etching, which holes are filledwith a conductive material 72 b such as solder or plating. In this way,the mounting parts 72 can be coupled to the probe sheet 6 by solderingor metal diffusion.

FIG. 15 shows an example of the pattern of the peripheral electrodes 5of the probe sheet 6 for conduction to the electrodes 50 a formed on thesurface of the multilayer wiring board 50 and the pattern of thecorresponding electrodes 50 a of the multilayer wiring board 50.

The wiring 20 and the peripheral electrodes 5 of the probe sheet 6 areformed by projecting the contact terminals from one of the surfaces ofthe polyimide sheet with the thin film wiring formed by the productionprocess shown in FIGS. 4A to 8D, for example, thereby to form the wiring20 in polyimide. Thus, the wiring 20, covered with polyimide, is keptout of contact with the electrodes 50 a formed on the surface of themultilayer wiring board 50 and not shorted. This group of the peripheralelectrodes 5 of the probe sheet 6 is set in position, using the knockpins 34 described above, with the electrodes 50 a connected to the innerwiring 50 b of the multilayer wiring board 50 by way of the through holevias 50 d, and held by the peripheral holding plate through the buffermember 31 thereby to press the two electrodes into contact.

A plurality of the peripheral electrodes 5 of the probe sheet 6 areformed for each electrode 50 a to reduce the possibility of contactfailure caused by, for example, an abnormal contact surface, foreignmatter or roughness thereby to secure stable contact. A plurality ofcontact terminals are provided for each peripheral electrode 5 in thecase where the electrode size allows. Otherwise, one contact terminalfor each peripheral electrode 5 may of course be formed.

In forming the probe sheet 6 through the production process shown inFIGS. 4A to 8D, the peripheral electrodes 5 can make up pyramidal ortruncated pyramidal contact terminals. As compared with the conventionalhemispheric plating bumps or planar electrodes in contact with eachother, therefore, a stable contact characteristic value can be realizedwith a low contact pressure pressure and hard contact terminals. At thesame time, the photolithography makes possible the connection with ahigh accuracy of the tip position. For this reason, the accuracy of thetip position is so high that simply by setting in position with thepositioning holes, the electrodes 50 a of the multilayer wiring board 50can be easily connected with high accuracy. Especially, the peripheralelectrodes 5 for connecting to the electrodes 50 a of the multilayerwiring board can be collectively formed on the same surface together asthe contact terminals 4 for connecting the wafer electrodes, resultingin a high efficiency.

Next, a semiconductor testing device using the probe card according tothe invention described above is explained with reference to FIG. 11.

FIG. 11 shows a general configuration of an testing system including thesemiconductor testing device according to the invention. FIG. 11 alsoshows a testing device for conducting the electrical characteristic testby applying the desired load on the surface of the wafer 1. Under thiscondition, the load of the spring probe 12 is imposed on the wholecontact terminals, and electrical testing signals are transmitted to andreceived from a tester (not shown) for inspecting the electricalcharacteristics of the semiconductor element through the contactterminals 4 in contact with the electrodes 3 of the wafer 1, the leadwires 20, the peripheral electrodes 5, the electrodes 50 a of the wiringboard 50, the internal wires 50 b and the connection terminals 50 c.

In the general configuration of the testing system, the probe card isconfigured as a wafer prober. This testing system includes a samplesupport system 160 for supporting the semiconductor wafer 1 to beinspected, a probe card 120 for supplying and receiving electricalsignals in contact with the electrodes 3 of the test object (wafer) 1, adrive control system 150 for controlling the operation of the samplesupport system 160, a temperature control system 140 for controlling thetemperature of the test object 1, and a tester 170 for testing theelectrical characteristics of each semiconductor element (chip) 2. Thesemiconductor wafer 1 has an arrangement of a multiplicity ofsemiconductor elements (chips), and a plurality of electrodes 3constituting external connection electrodes are arranged on the surfaceof each semiconductor element. The sample support system 160 isconfigured of a sample stable 162 arranged substantially horizontallywith the semiconductor wafer 1 removably placed thereon, a verticalshaft 164 arranged vertically to support the sample table 162, avertical drive unit 165 for vertically driving the vertical shaft 164,and an X-Y stage 167 for supporting the vertical drive unit 165. The X-Ystage 167 is fixed on a housing 166. The vertical drive unit 165 isconfigured of, for example, a stepping motor. The horizontal andvertical positioning operation of the sample table 162 is performed bycombining the movement of the X-Y stage 167 in a horizontal plane andthe vertical movement by the vertical drive unit 165. Also, a rotarymechanism not shown is arranged on the sample table 162, so that thesample table 162 is rotatable in the horizontal plane.

A probe system 120 is arranged above the sample table 162. As a specificexample, the probe card 120 and the multilayer wiring board 50 shown inFIGS. 2A, 2B are arranged in opposed parallel relation to the sampletable 162. Each contact terminal 4 is connected to the correspondingconnection terminal 50 c on the wiring board 50 through the lead wire 20and the peripheral electrode 5 on the probe sheet 6 of the probe card120 and also through the electrode 50 a and the internal wire 50 b ofthe multilayer wiring board 50 on the one hand, and to the tester 170through a cable 171 connected to the connection terminal 50 c on theother hand.

In order to prevent the displacement due to the temperature differencebetween the wafer heated to the desired temperature by a heater and theprobe sheet formed with the contact terminals in contact with the waferelectrode for conducting the electrical signal test and to set them inposition accurately within a short time, a temperature-controllable heatgenerator may be formed beforehand on the surface of or in the probesheet or the probe card. The heat generator may be formed of a metalmaterial such as Ni—Cr or a conductive resin having a high resistancedirectly on the probe sheet or the multilayer wiring board layer, or asheet formed with the particular material is held in the probe sheet orattached on the probe card. Also, a liquid heated as a heat generator issupplied into a tube in a heat block in contact with the probe card.

Unlike in the conventional method in which the temperature of the probecard is determined by the heat radiation from a heated wafer and thecontact at the time of probing, the probe sheet is kept at the testingtemperature independently as described above. Thus, the temperaturedifference between the wafer and the probe sheet at the time of testingcan be avoided, thereby making possible accurate probing with highpositional accuracy.

The drive control system 150 is connected to the tester 170 through thecable 172. Also, the drive control system 150 sends a control signal toand controls the operation of the actuator of each drive unit of thesample support system 160. Specifically, the drive control system 150includes an internal computer and controls the operation of the samplesupport system 160 in accordance with the progress information of thetest operation of the tester 170 transmitted through the cable 172.Also, the drive control system 150 includes an operating unit 151 forreceiving the input of various instructions on the drive control such asan instruction for manual operation.

The sample table 162 includes a heater 141 for heating eachsemiconductor element 2. The temperature control system 140 controls thetemperature of the semiconductor wafer 1 mounted on the sample table162, by controlling the heater 141 or the cooling jig of the sampletable 162. Also, the temperature control system 140 includes anoperating unit 151 to receive the input of various instructions, forexample, for manual temperature control operation. Thetemperature-controllable heat generator arranged in a part of the probesheet or the probe card and the heater 141 of the sample table 162 maybe operatively interlocked with each other for temperature controloperation.

The operation of the semiconductor testing device is explained below.First, the semiconductor wafer 1 to be inspected is set in position onthe sample table 162. By controlling the drive operation of the X-Ystage 167 and the rotary mechanism, the group of the electrodes 3 formedon a plurality of semiconductor elements arranged on the semiconductorwafer 1 is set in position just under a multiplicity of contactterminals 4 juxtaposed on the probe card 120. After that, the drivecontrol system 150 activates the vertical drive unit 165 and moves thesample table 162 upward to the state where the whole surface of themultiplicity of the electrodes (contacted members) 3 is pushed up byabout 30 to 100 μm from the point where the particular surface comesinto contact with the forward end of the contact terminals. In this way,an area 4 a where the multiplicity of the contact terminals 4 arejuxtaposed on the probe sheet 6 is expanded, and each forward end of themultiplicity of the contact terminals 4 having secured the flatness ofhigh accuracy is projected in parallel following the surface of thegroup (whole) of the multiplicity of the electrodes 3 arranged on thesemiconductor element by a compliance mechanism (pressure mechanism).Thus, the contact pressure is applied based on the uniform load (about 3to 150 mN per pin) following each contacted member (electrode) 3arranged on the semiconductor wafer 1, so that each contact terminal 4and each electrode 3 are connected with a low resistance (0.01 Ω to 0.1Ω).

Further, the operating current and the operation test signal aretransmitted between each semiconductor element 1 formed on thesemiconductor wafer 1 and the tester 170 through the cable 171, thewiring board 50 and the contact terminals 4 thereby to determine whetherthe operation characteristics of the semiconductor element aresatisfactory or not. Further, this series of test operation is conductedfor each of a plurality of the semiconductor elements formed on thesemiconductor wafer 1 thereby to determine whether the operationcharacteristics are satisfactory or not.

Finally, a method of producing a semiconductor device including thetesting steps or the testing method using the aforementionedsemiconductor testing device is explained with reference to FIG. 12.

A method of producing a semiconductor device according to the inventioncomprises the steps of building a circuit in a wafer and formingsemiconductor elements, test the electrical characteristics of aplurality of the semiconductor elements 2 collectively in wafer form bythe semiconductor testing device according to the invention, dicing andseparating the wafer into each semiconductor element, and sealing thesemiconductor elements with resin or the like.

Another method of producing a semiconductor device according to theinvention comprises the steps of building a circuit in a wafer andforming semiconductor elements, test the electrical characteristics of aplurality of the semiconductor elements 2 collectively in wafer form bythe semiconductor testing device according to the invention, and dicingand separating the wafer into each semiconductor element.

Still another method of producing a semiconductor device according tothe invention comprises the steps of building a circuit in a wafer andforming semiconductor elements, sealing the wafer in resin or the like,and collectively testing the electrical characteristics of a pluralityof the semiconductor elements 2 formed on the sealed wafer by thesemiconductor testing device according to the invention.

A further method of producing a semiconductor device according to theinvention comprises the steps of building a circuit in a wafer andforming semiconductor elements, sealing the wafer in resin or the like,collectively testing the electrical characteristics of a plurality ofthe semiconductor elements 2 formed on the sealed wafer by thesemiconductor testing device according to the invention, and dicing andseparating the wafer into each semiconductor element.

At the step of testing the electrical characteristics of eachsemiconductor element 2 in the method of producing the semiconductordevice described above, a satisfactory contact characteristic can beobtained with high positional accuracy by use of the probe carddisclosed herein.

Specifically, the test is conducted using the pyramidal or truncatedpyramidal contact terminals 4 plated, using as a mold member, the holesformed by anisotropic etching of a crystalline board. Thus, a stablecontact characteristic can be realized with a low contact pressure, andthe semiconductor element located below can be inspected without beingdamaged. Also, due to the structure in which a plurality of the contactterminals 4 are surrounded by the metal film 30 a, the contact terminalsare not subjected to an excessive stress at the time of test operation,and therefore an accurate contact with the electrodes of eachsemiconductor element 2 is realized. The plurality of the semiconductorelements 2 may also tested collectively.

In view of the fact that the probing marks on the electrode of thesemiconductor element 2 are in the form of small dots (pyramidally ortruncated pyramidally formed holes), the electrode surface maintainsflat areas free of dents, thereby making it possible to meet therequirement of a plurality of tests by contact as shown in FIG. 12.

The invention achieved by the present inventor is specifically explainedabove based on embodiments thereof. This invention, however, is notlimited to those embodiments and can of course be variously modifiedwithout departing from the scope and spirit thereof.

The representative effects of the invention disclosed in thisapplication are briefly explained below.

-   (1) An testing device is provided in which the accuracy at the tip    position of the contact terminals is secured and a semiconductor    element having an electrode structure having narrow pitches can be    positively tested.-   (2) A method of producing a semiconductor device is provided in    which a satisfactory connection to the electrodes is secured and the    reliability is improved.

BRIEF DESCRIPTION OF THE DRAWINGS

[FIG. 1] A is a perspective view showing a wafer to be contacted with anarrangement of semiconductor elements (chips), and B a perspective viewshowing a semiconductor element (chip) in the wafer.

[FIG. 2] A is a sectional view showing the essential parts of the probecard according to a first embodiment of the invention, and B an explodedperspective view illustrating the essential parts in A.

[FIG. 3] A is a sectional view showing the essential parts of the probecard according to a second embodiment of the invention, and B anexploded perspective view illustrating the essential parts in A.

[FIG. 4] A to H show a production process, step by step, to form theprobe sheet portion of a probe card according to the invention.

[FIG. 5] A to E show another production process, step by step, to formthe probe sheet of a probe card according to the invention.

[FIG. 6] A to G show still another production process, step by step, toform the probe sheet of a probe card according to the invention.

[FIG. 7] A to C show yet another production process, step by step, toform the probe sheet of a probe card according to the invention, D1 andE1 partial sectional views schematically showing the area formed withthe contact terminal portion of the probe sheet of the probe cardaccording to the invention, D2 a plan view showing a part of the areaformed with the contact terminal portion in D1 as taken from the lowersurface in D1, and E2 a plan view showing a part of the area formed withthe contact terminal portion in E1 as taken from the lower surface inE1.

[FIG. 8] A to D show a further production process, step by step, to formthe probe sheet portion of a probe card according to the invention.

[FIG. 9] A sectional view schematically showing a probe sheet formedwith a ground layer in the probe card according to the invention.

[FIG. 10] A sectional view schematically showing another probe sheetformed with a ground layer in the probe card according to the invention.

[FIG. 11] A diagram showing a general configuration of the testingsystem according to an embodiment of the invention.

[FIG. 12] A process diagram showing the testing process of asemiconductor device according to an embodiment.

[FIG. 13] A schematic diagram showing a method of assembling the probecard according to the invention.

[FIG. 14] A is a sectional view showing the essential parts of the probecard according to an embodiment of the invention, and B a plan viewschematically showing, in enlarged form, the wiring of the portion of Awhere the parts are mounted.

[FIG. 15] An example of the peripheral electrode pattern on the surfaceof a multilayer wiring board and the wiring pattern on the probe sheetaccording to the invention.

1. A method of producing a semiconductor device, comprising the stepsof: building a circuit in a wafer and forming a plurality ofsemiconductor elements; contacting a plurality of contact terminalsformed within a first area surrounded by a first metal film of a probesheet to each of a plurality of electrodes provided at the semiconductorelements to test electrical characteristics of each of the semiconductorelements; and dicing and separating the wafer into the semiconductorelements; wherein the electrical characteristics of each of thesemiconductor elements are tested by pushing the first area surroundedby the first metal film while fixing a second metal film formed so as tosurround the first metal film of the probe sheet thereby to make theplurality of the contact terminals contact with the electrodes of thesemiconductor element to perform the testing, wherein the first metalfilm has a linear expansion coefficient substantially the same as alinear expansion coefficient of the wafer, and wherein the first metalfilm is formed by 42 alloy or invar.
 2. A method of producing asemiconductor device according to claim 1, wherein the plurality of thecontact terminals are pyramidal or truncated pyramidal.
 3. A method ofproducing a semiconductor device according to claim 1, wherein theplurality of the contact terminals are formed using, as a mold member,the holes formed by anisotropic etching of a crystalline board.
 4. Amethod of producing a semiconductor device, comprising the steps of:building a circuit in a wafer and forming a plurality of semiconductorelements; contacting a plurality of contact terminals formed within afirst area surrounded by a first metal film of a probe card having aprobe sheet to each of a plurality of electrodes provided at thesemiconductor elements to test electrical characteristics of each of thesemiconductor elements; and dicing and separating the wafer into thesemiconductor elements; wherein the electrical characteristics of eachof the semiconductor elements are tested by pushing the first areasurrounded by the first metal film while fixing a second metal filmformed so as to surround the first metal film of the probe sheet therebyto make the plurality of the contact terminals contact with theelectrodes of the semiconductor element to perform the testing, whereinthe first metal film has a linear expansion coefficient substantiallythe same as a linear expansion coefficient of the wafer, and wherein thefirst metal film is formed by 42 alloy or invar.
 5. A method ofproducing a semiconductor device according to claim 4, wherein the probecard further includes a means for applying pressure to an area formedwith the first metal film and an area formed with the plurality of thecontact terminals of the probe sheet, and wherein the electricalcharacteristics of each semiconductor element are tested by the pressureapplication means applying pressure to the area formed with the firstmetal film and the area formed with the plurality of the contactterminals of the probe sheet while making the plurality of the contactterminals in contact with the electrodes of the semiconductor element.6. A method of producing a semiconductor device according to claim 4,wherein the plurality of the contact terminals are pyramidal ortruncated pyramidal.
 7. A method of producing a semiconductor deviceaccording to claim 4, wherein the plurality of the contact terminals areformed using, as a mold member, the holes formed by anisotropic etchingof a crystalline board.